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Biomedical subjects

Y Handa

Publications and source records attributed to Y Handa.

At least 253 records · Page 14Linked to original sources
PubMed1976

A consideration of the racial incidence of congenital dyschromats in males and females.

The female incidence of congenital dyschromats corresponds to the square of the males in the Northern European populations, but this relation is not always true in the non-white races. The above-mentioned facts in the non-white races which are theoretically strange are considered to be caused by an anti-glare factor of pigment epithelium in their eyes, on the assumption that the abnormal color sense of color defectives may be a special form of visual dysfunction glare pointed out by IINUMA.

Asian People↗
PubMed1975

Experimental cerebral vasospasm in cats: modification by a new synthetic vasodilator YC-93.

Effects of a new synthetic vasodilator, YC-93, a derivative of 1. 4-dihydropyridine, on experimental cerebral vasospasm, were studies in cats. A topical administration of YC-93 solution was found to rapidly reverse the spasm of the basilar artery induced with a subarachnoi application of fresh blood, serotonin or porstaglandin F2 alpha. Pretreatment of the basilar artery with YC-93 prevented the development of experimental vasospasm with all these agents.

Animals↗
PubMedDate not supplied

Cerebrovascular contractility after clot removal in monkey subarachnoid haemorrhage.

1. The effects of mechanical clot removal during early surgery on pharmacological cerebrovascular reactivity after subarachnoid haemorrhage (SAH) were investigated in the monkey. 2. Contractions to potassium chloride, 5-hydroxytryptamine and noradrenaline in rings of proximal parts of middle cerebral arteries (MCP), surrounded with clot, and basilar arteries (BAP), far from the clot, were examined 7 days after SAH, in which an autologous blood clot was bilaterally placed around major cerebral arteries. 3. Compared with the sham-operated group, contractions in the clot removal groups at 48 and 72 h after SAH were reduced in MCP and enhanced in BAP. 4. These results suggest that divergent vascular contractility may occur according to the distance between artery and clot if the clot is removed later than 48 h after SAH.

Animals↗
PubMedDate not supplied

Cerebral blood flow studies using N-isopropyl I-123 p-iodoamphetamine.

Twenty patients with stroke were studied for cerebral blood perfusion abnormalities using N-isopropyl I-123 p-iodoamphetamine (IMP) and rotating dual gamma camera emission computed tomography (ECT). After a single scan, multiple transverse, coronal and sagittal section images were reconstructed with a minicomputer. In eighteen patients, we determined the values of regional cerebral blood flow (rCBF) in the region of interest using an image. Transmission computed tomography (CT) studies were also performed on the same day. ECT showed cerebral perfusion abnormalities in all cases, while CT showed abnormalities in only 10 cases. This technique seems to be useful for evaluating the rCBF in the deep brain.

Adolescent↗
PubMedDate not supplied

Effect of whole-body hyperthermia on the development of peritumoral brain oedema.

The effect of whole-body hyperthermia on the development of peritumoral brain oedema and intracranial pressure was studied in cats with intracerebral transplanted tumour. Whole-body hyperthermia was achieved by means of extracorporeal circulation. The temperature within the brain tumour tissue was increased to 41.8 +/- 0.15 degrees C (mean +/- SD) for 2 h. Measurements of brain water content revealed that hyperthermia worsened the degree of peritumoral brain oedema. Microscopical observation demonstrated that extravasation of horseradish peroxidase, indicating disruption of the blood-brain barrier in the oedematous region, was more severe in animals exposed to hyperthermia than in non-treated animals. Intracranial pressure significantly increased from 13.5 +/- 5.26 mmHg to 25.8 +/- 6.16 mmHg (p < 0.05) during hyperthermia, although it was controlled at 20.7 +/- 2.60 mmHg by continuous infusion of glycerol. The results suggest that whole-body hyperthermia acting on a brain-bearing tumour caused an increase in intracranial pressure due to worsening of the degree of peritumoral vasogenic type of brain oedema. We emphasize that whole-body hyperthermia may be performed with careful monitoring of intracranial pressure for patients who have brain tumour.

Animals↗